1. Field of the Invention
The present invention relates to a cutting mat, on which a sheet of paper, cloth or the like is cut with a cutter knife. In particular, the invention relates to a rotary cutting mat, wherein the upper face of the mat can be rotated to improve efficiency of cutting work.
2. Description of the Related Art
A rotary cutting mat having a rotatable upper face is known, for example from Japanese Utility Model Registration No. 3022789.
The rotary cutting mat disclosed in Japanese Utility Model Registration No. 3022789 comprises a base plate and a rotary mat, which are so connected to each other with a rivet, as to be rotatable relative to each other. The reverse side of the base plate is roughened, such that the base plate does not slide on a working table, unintentionally. The rotary mat is rotated on such the base plate. That is, an operator puts a sheet of paper, cloth or the like on the rotary mat and cuts the same.
Accordingly, with appropriately rotating the rotary mat depending on a cutting direction, the operator always can conduct the cutting operation in easy working posture, without moving himself. In this way, with the rotary cutting mat, the efficiency of cutting work can be improved.
However, the rotary cutting mat in Japanese Utility Model Registration No. 3022789 confronts the following problems, since a rivet member is used to connect the base plate and the rotary mat.
(1) Firstly, since a sheet of paper, cloth or the like to be cut is placed on the upper surface of the rotary mat, the head of the rivet should not be exposed on the upper surface of the rotary mat. This is because: if a rivet head is exposed on the upper surface of the rotary mat, the upper surface in such the region can not serve as a cutting mat. To solve this problem, the rotary mat is made up having a multi-layer structure, and the rivet head is buried in the multi-layer structure. Therefore, the structure of the mat becomes complicated, which increases the number of the components of the mat and the number of the manufacturing steps, resulting in higher cost.(2) Secondary, a region of the upper surface of the mat corresponding to the rivet head buried in the multi-layer structure is slightly raised. Thus, the upper surface of the mat can not be kept in flat, and thus, cutting lines can be easily deflected on such the raised region of the mat.